1. Field of Invention
This invention relates to animal feed supplements and, in particular, to animal feed supplements in suspension containing a substantial quantity of water insoluble nutrients.
2. Brief Statement of the Prior Art
The value of sugar-containing supplements as an energy source in animal diets has been recognized for many years. Phosphates have been added to the supplements as a source of dietary phosphorous; urea has been added to supply non-proteinous nitrogen; and fats have been included, as described in U.S. Pat. No. 2,793,952. Vitamins have been included in these supplements as described in U.S. Pat. No. 2,807,546.
A common practice is to suspend solids in liquid feeds with clays such as attapulgite or bentonite. The clays must be used in large quantities, typically about 2 to 3 weight percent based on the weight of the supplement. Since the clays are inert, the user incurs a substantial cost for transportation and storage of an ingredient having no nutrient value. The clays must also be dispersed in deionized water and slurried in the liquid feed with high shear stirring, which increases manufacturing costs.
U.S. Pat. No. 4,267,197 discloses a method of incorporating a substantial quantity of water insoluble nutrients in the liquid supplements while preserving the desirable liquid properties of the supplement. Examples of suitable water insoluble additives are calcium sources such as calcium carbonate, or calcium sulfate, and monisan, a water insoluble drug additive.
The method used in the aforementioned patent is to gel the molasses by adding ammonium orthophosphate and to add the insoluble solids to the gel. Although the method of this patent has been practiced quite successfully on a commercial scale, there is a considerable resistance to use of ammonium compounds in feed supplements, particularly for dairy applications.
Liquid feed supplements have also been prepared by the addition of water, ammonium polyphosphate and calcium chloride to molasses, as described in U.S. Pat. No. 3,962,484. If the calcium chloride is added to molasses before ammonium polyphosphate, excessive gelling and precipitation will occur, as reported in depth in: "Calcium Chloride in Liquid Feed Supplements" NFIA Counter Oct. 14-16, 1973, pp 115-129, by Grosso et al, the inventors named in the aforementioned patent.
It is also known that solid feed supplements can be obtained by the addition of certain gelling agents to molasses. This practice has resulted in commercial acceptance of "poured chemical blocks". The poured chemical blocks are either soft blocks formulated with lime and phosphoric acid at an acidic pH (3.0 to 6.5) as described in U.S. Pat. Nos. 4,027,043 and 4,160,041, or hard blocks in which the formulation contains substantial amounts of alkaline additives, usually magnesium oxide, as described in U.S. Pat. Nos. 4,431,675; 4,171,385; 4,171,386; and 4,265,916; New Zealand Patent No. 170505; Australian Patent No. 438,073; and U.K. Patent No. 1,356,954. Hard blocks prepared by the methods of the latter patents have pH values from 9.5 to 10.5.
All of the aforementioned supplements have contained appreciable quantities of molasses and minimal quantities of water. The solid supplements have contained sufficient molasses to provide mixtures of 60.degree. Brix or greater. Molasses has also been the major ingredient in the liquid supplements, which have molasses concentrations of 55.degree. Brix or greater.
Molasses is desired to impart palatibility to the supplements. It also has nutritional value as a source of energy. Molasses is often costly and its pricing and availability is controlled by only a few suppliers. Consequently, the animal feed supplement market has been dependent on molasses pricing and supply.